Chaser



J. J. FLYNN.

CHASER.

APPLICATION FILED OCT. 25. 1919. 1,350,862. Patented Aug. 24, 1920.

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UNITEDSTATES JOHN J. FLYNN, OF PROVIDENCE, RHODE ISLAND.

CHASER.

Application filed October 25, 1919.

To all whom it may concern:

Be it known that I, JOHN J. FLYNN, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certam new and useful Improvements in Chasers, of which the following is a specification.

My invention relates to chasers for use in threading tools and particularly in that type of tools wherein the yielding chaser, cm braced bya spring collar, is impelled against the work by a cam collar engaging a cam face on the chaser, and is released from the work by the escape of a flange on the chaser from engagement with the collar. A threading tool of this type is shown in my prior U. S. Patent No. 1,259,504 issued March 19, 1918.

In chasers of this type repeated regrinding of the, teeth gradually forms a throat cut of such excessive length upon the lower extremity of the front end face, as to render the chaser useless for work of certain kinds. The essential object of my invention is to enable the chaser to still be utilized as well as originally, and prolong its period of utility.

My invention consists, therefore, in the means for producing the results above specified substantially as hereinafter described and claimed, and as shown in the accom panying drawings, which constitute a part of this invention, wherein Figures 1 and 2 are front and back end elevations respectively of my novel chaser,

I Fig. 3, a side elevation of the same, and

Figs. 4 and 5, top and bottom plan views respectively of the same.

Like characters of reference indicate like parts throughout the views.

In detail the chaser comprises an oblong body 7 having its front and rear surfaces, 8 and 9, in parallel planes. The lower end of the body is, in this instance, laterally retracted forming a ridge 10 extending the width of the body provided throughout its length with a series of transversely disposed cutting teeth 11. The number of ridges 10 are immaterial. Upon the top end of'the Specification of Letters Patent.

Patented Aug. 241 1920. Serial No. 333,347.

body midway its end surfaces there is a transversely disposed shoulder or flange 13 provided with an arcuate end facels and rectangular in cross section, extending the width of the body. At one side of the flange 13 is an intermediate rectangular shoulder 15 also disposed transversely of the body provided with an arcuate end face 16. The shoulder 15 is, however, shorter than the flange; that is to say its end face 16 is located nearer the center of the body than is the face 14. A third or outermost shoulder 17 has its side face coincident with the end face 8 of the body and isdisposed transversely'of the latter. This shoulder is co centric to the other two shoulders and has a resultant eccentrically curved, or inclined,

or cam end face 18. This face is more remote from the upper extremity of the chaser than is the face 16. The three described shoulders constitute a series of steps receding from the center to the outer 'end face of the body. Adjacent and below the flange 13 is an intermediate shoulder 20 with an end face 21 similar in all respects to the intermediate shoulder above described. Below the shoulder 20 is a shoulder 22 with its side face coincident with face 9 and eccentric to the shoulders113 and 20. This shoulder has aneccentrically curved, or inclined, or cam face more remote from the top of the chaser than face 21. The three shoulders 13, 20, and 22 constitute a series of steps receding from the center to the inner endface of the body.

The chaser is initially mounted in the threading tool so that the cam face 23 for an indefinite period receives the thrust from the impelling cam collar. At intervals during this period the chaser is removed and its teeth regrouud, thus gradually increasing the throat cut at the front end surface of the carrier, as indicated by the broken line 2 1. This extreme throat cut would render the chaser useless for cutting adjacent any shouldered work, but by virtue of the described construction the chaser may be withdrawn and returned to place with its front and rear end faces reversed, whereupon out ting upon Work adjacent a shoulder may be of Math upon its lower end, and providedupon its upper end midway its end faces with a transversely dlsposedareuate flange, and each slde of the flange W1th an arcuate intermediate shoulder receding from the 10 flange, and exterior each intermediate shoulder with an end shoulder disposed 8CCGI1HL- oally to the flange and to the other shoulders. .7

In testimony whereof I have aflixed my 15 signature.

JoHN J. FLYNN. 

